Senators turned back a move by Majority Leader Harry Reid, D-Nev., to limit debate on a three-month extension of the unemployment insurance benefits after the two parties traded barbs about the amendment process proposed by Reid. The Senate voted largely along party lines, 55-45, on a debate-limiting motion, short of the 60 votes needed to advance the bill.

Reid's proposal to vote on a series of amendments hit a snag when Republicans said it simply was not something they could agree to, with Minority Leader Mitch McConnell, R-Ky., contending Reid was trying to stack the deck.

"It is pretty clear that the majority leader is not interested in having an open amendment process. and of course the consent that's just been offered requires that all of the Republican amendments be at a 60-vote threshold and that the final passage be at 51. In other words, guaranteed to fix the result in such a way that doesn't give the minority a fair chance," McConnell said. "I mean, who is to say a number of our amendments might be appealing to members on the Democratic side. That's probably why the majority leader wants it to be at 60: because he's afraid they may pass."

Senators in both parties filed amendments to the unemployment extension measure.

Reid wanted to ensure that a substitute version of the extended benefits could ultimately pass with a simple majority vote, rather than with a 60-vote threshold vote where the outcome would be more dubious.

"It's a one-sided deal," Sen. Charles E. Schumer, D-N.Y., told reporters before the floor exchange about what the Republicans want to see. "Three of the five people who wanted amendments said they wouldn't vote for cloture."

"It's pretty obvious that if they are still going to filibuster bills ... They said the reason they blocked bills is because they don't get amendments. Now, we're giving them amendments, and they're still blocking the bills," Schumer said.